[Bug] Claude Code Max 20x 5-hour session usage accounting disproportionately high with parallel sessions

Bug Description
Claude Code Max 20x usage accounting issue, May 3, 2026. I am on Max 20x and paid again today, but Claude Code usage is still being consumed extremely quickly. Observed usage after the new paid period/payment: - Current 5-hour session went from 34% to 56% shortly after - Weekly All models went from 18% to 21% - Weekly Sonnet-only went from 24% to 28% - Claude Design remains 0% Earlier, immediately after reset, the session went: - 28% after first visible prompt/action - 50% after second visible prompt/action - 100% after only a few visible prompts/actions At the same time weekly usage was still much lower, so this looks like 5-hour session accounting is burning disproportionately fast. Claude Code /usage shows: - 95% of usage while 4+ sessions ran in parallel - 27% from subagent-heavy sessions - 22% at >150K context - per-model breakdown unavailable / rate limited I understand that parallel sessions, subagents, and large contexts can increase usage. But the current UX/accounting is not actionable: - no clear per-session/per-process breakdown - no warning before multiple Claude Code sessions burn the 5-hour Max 20x window - web UI changed/reset unexpectedly and temporarily hid Sonnet-only / Design rows while CLI usage still showed consumption - paid Max 20x quota becomes unusable for normal work Please escalate to a human/support engineer for account-level usage accounting review. I need to know whether this is expected behavior, a bug, or an accounting issue, and whether Anthropic can reset/refund incorrectly or unintentionally consumed quota. Related GitHub evidence: - anthropics/claude-code#55597 - anthropics/claude-code#55053 Environment: - Plan: Max 20x - Claude Code: 2.1.126 - Windows / PowerShell - Timezone: Europe/Kiev

Environment Info

• Platform: win32
• Terminal: vscode
• Version: 2.1.126
• Feedback ID: f34dee8f-e57c-47e2-8052-e3deba57972e

Errors

[{"error":"Error: File does not exist. Note: your current working directory is C:\\Users\\anton\\Desktop\\artbrain-shop.\n    at call (B:/~BUN/root/src/entrypoints/cli.js:4922:11399)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-05-03T05:55:33.714Z"},{"error":"Error: File does not exist. Note: your current working directory is C:\\Users\\anton\\Desktop\\artbrain-shop.\n    at call (B:/~BUN/root/src/entrypoints/cli.js:4922:11399)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-05-03T05:55:33.862Z"},{"error":"Error: ENOENT: no such file or directory, unlink 'C:\\Users\\anton\\AppData\\Local\\Temp\\claude\\C--Users-anton-Desktop-artbrain-shop\\72899fbb-2127-41de-af39-0be5af6ddf6b\\tasks\\af5467028a910c80b.output'\n    at async <anonymous> (B:/~BUN/root/src/entrypoints/cli.js:8754:299)","timestamp":"2026-05-03T05:57:25.462Z"},{"error":"Error: ENOENT: no such file or directory, unlink 'C:\\Users\\anton\\AppData\\Local\\Temp\\claude\\C--Users-anton-Desktop-artbrain-shop\\72899fbb-2127-41de-af39-0be5af6ddf6b\\tasks\\a8d3fea08aed7906c.output'\n    at async <anonymous> (B:/~BUN/root/src/entrypoints/cli.js:8754:299)","timestamp":"2026-05-03T05:57:48.176Z"},{"error":"Error: ENOENT: no such file or directory, unlink 'C:\\Users\\anton\\AppData\\Local\\Temp\\claude\\C--Users-anton-Desktop-artbrain-shop\\72899fbb-2127-41de-af39-0be5af6ddf6b\\tasks\\ae2e1ed14bb02880b.output'\n    at async <anonymous> (B:/~BUN/root/src/entrypoints/cli.js:8754:299)","timestamp":"2026-05-03T05:58:02.425Z"},{"error":"Error: ENOENT: no such file or directory, unlink 'C:\\Users\\anton\\AppData\\Local\\Temp\\claude\\C--Users-anton-Desktop-artbrain-shop\\72899fbb-2127-41de-af39-0be5af6ddf6b\\tasks\\aab0da37978d392a1.output'\n    at async <anonymous> (B:/~BUN/root/src/entrypoints/cli.js:8754:299)","timestamp":"2026-05-03T05:58:18.334Z"},{"error":"UU7: Diagnostics file path mismatch: expected C:\\Users\\anton\\Desktop\\artbrain-shop\\src\\lib\\stock.ts, got file://c:\\users\\anton\\desktop\\artbrain-shop\\src\\lib\\stock.ts/)\n    at beforeFileEdited (B:/~BUN/root/src/entrypoints/cli.js:4948:25301)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-05-03T06:13:42.753Z"},{"error":"UU7: Diagnostics file path mismatch: expected C:\\Users\\anton\\Desktop\\artbrain-shop\\src\\lib\\auth\\dal.ts, got file://c:\\users\\anton\\desktop\\artbrain-shop\\src\\lib\\auth\\dal.ts/)\n    at beforeFileEdited (B:/~BUN/root/src/entrypoints/cli.js:4948:25301)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-05-03T06:13:45.420Z"},{"error":"UU7: Diagnostics file path mismatch: expected C:\\Users\\anton\\Desktop\\artbrain-shop\\CRM-WMS-PLAN.md, got file://c:\\users\\anton\\desktop\\artbrain-shop\\crm-wms-plan.md/)\n    at beforeFileEdited (B:/~BUN/root/src/entrypoints/cli.js:4948:25301)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-05-03T06:15:54.133Z"},{"error":"Error:…

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